Dental apparatus



Nov. 7, 1950 H. SPIRO 2,529,429

DENTAL APPARATUS Filed April 18, 1949 INV'ENTOR HARRY SFn o By QM w ATTORNEY Patented Nov. 7, 1950 UNITED STATES PATENT OFFICE DENTAL APPARATUS Harry Spiro, Chicago, Ill.

Application April 18, 1949, Serial No. 88,169

11 Claims.

This invention relates to dental apparatus and particularly to impression trays. In the making of dental prosthetics, such as bridges and partial plates, it is essential that a good impression be made. In many instances, poor impressions result from the apparatus now available and used in the art. Thus, conventional trays for holding impression forming materials all rely upon a large amount of excess impression-forming material for the success of the procedure.

It is essential to eliminate air bubbles at the surface to be copied. To this end it has been the practice to rely upon a large amount of excess impression-forming material. Thus, as the tray was forced into final position, surplus impression-forming material would be forced out from the edges of the tray. The surplus material, while performing a useful function, frequently made the patient uncomfortable to the point of gagging and thus rendered the making of a good impression difficult.

This invention provides a tray construction which makes it possible to improve the quality of an impression while reducing the amount of surplus material. It is thus possible to make an impression with far less inconvenience to the patient so that a good impression may be obtained the first time. In addition, the resulting impression obtained by the use of my invention is less likely to have flaws than is true with impressions made by conventional means.

My invention provides for maintaining theimpression-forming material under some pressure at the impression surfaces, such as teeth and gingiva, and permits excess impression-forming material to, flow under pressure along the impression surface and then free of the tray. Thus any air bubbles normally occurring at the necks of the teeth will be washed or flown away and the material itself will finally rest in intimate contact with the impression surface. This is obtained without the use of an excessive quantity of impression-forming material so that the final impression may be made with less discomfort.

In general, my invention provides, in addition to a conventional tray, an auxiliary member telescopically arranged with respect to the tray side so that in effect there is formed an extension of the tray side thus rendering the tray initially deeper than normal. In the use of my invention, the tray and its extension are filled with impression-forming material and inserted into the oral cavity for making an impression. Thereafter force is exerted upon the tray proper to telescope the extension inwardly toward the tray. Thus a flow of impression-forming material along the tooth and gingival surfaces is generated. This fiow of material is sufiicient so that any air bubbles are removed. Due to the pressure on the impression material, the material will penetrate all crevices and nooks in the impression surface to provide a final impression which is true in all details.

The invention may be applied to any type of tray whether for use with maxilliary or mandibular dentures or bridges and may be used with either plain or water-jacketed types of trays.

In order that the invention may be fully understood it will now be explained in connection with the drawings wherein Figure 1 is an isometric view of a tray embodying the present invention for use in taking a maxillary impression. Figure 2 is a detail of the hinge portion of the structure shown in Figure 1. Figure 3 is an isometric view generally similar to Figure l but showing a tray for use in taking a mandibular impression. Figure 4 is a detail of the hinge portion of the structure shown in Figure 3. Figure 5 is a side detail of the clamp portion of the structure shown in Figure 1. Figure 6 is an end view of the clamp portion of the structure shown in Figure 5. Figure '7 is a perspective detail of a tray embodying the present invention for use in making a partial denture or bridge. Figure 8 shows a modification.

Referring first to Figures 1 and 2, the tray comprises ridge portion Hl having vault portion I] and flange portion 52. It will be noted that flange portion l2 varies from a minimum height at the heel of the tray to a maximum at labial portion I3 of the tray as seen in Figures 5 and 6. The tray has handle i5 rigidly attached'to the bottom thereof below labial portion [3. This structure is conventional.

Hingedly secured at i? and i8 is extension 20 consisting of a curved portion extending around on the inside surface of the flange of the tray. Portion 20 may extend on the outside if desired. Portion 2B is preferably provided with a large number of apertures, the size and spacing being varied to suit requirements. Instead of perforations, roughening of the inside surface may be provided. This is to provide for mechanical gripping of the compound- Extension 2i] may be turned on its hinges or pins to swingup from the labial portion of the tray. In the normal use of the tray, portion 20 need not extend very far up from the tray edge and its maximum outer position for normal use may be as shown in Figures 5 and 6. For cleaning purposes and for 3 initially filling the tray with impression-forming material, it may be advisable to swing portion clear of the tray.

It is desirable to provide means for retaining portion 20 in a predetermined open position as shown in Figures 5 and 6. To this end, tray flange I3 may carry clip 23 to which portion 25 is attached.

Portion 25 has spring tongue 26 which has looking portion 221 cooperating withindentation 28 in the tray flange for'temporarily locking portion 20 in its upper position. Handle 30 for the locking clip is provided for releasing the lock and for exerting the necessary force uponportion 20 relative to tra In so that the two may be moved predetermined to a closed position. Thus a gauge or measuring action=may.be;provided.

Referring now to Figures 3 and 4, the same general structure is shown with the exception that ridge H! of the tray is bounded by lingual .flangezportions ll "leaving an 'open'ispace for :clearin'gtongue tissue. ;In this :construction, shownzinifi'igures 3' 'and 4, portion 2fl' is:hinged- .iy-ssecuredzzbyzpin l'lrand l8. '1-Itis1underst0od,

:however; that the'same general hinge astructure -shown-in;iEigure:limay be used in Figures. 3..and"4. In the:construction shown in: Figures 3 and.-4;portion 26 has portion 2| extending over the;;hinge or -pin.- and-joined toportiomZZ' forming the upstanding inside boundar of the .hinge' portion.

'Z'I'Il the:modification.-.shown-in Figures 3' and 4, the.-same :clip-.structure may be used as-shownin Figure .1. :Again itmayfoe desirable-to swing portionz-Zfl clear'of the tray when initially fillingtthezsame. .In:this modification it w-illbe .noted ,that;portion- 20 formswanextension for the tray side at both the .innerand outerparts of the .tray.

.;Referring nowrto Figure 7 thereis shown a constructionzwhichimay be used in=connection with makingaan impression for a bridge. ,This construetionseomprises tray. which may beof the :water-jacketedtype, havingwater inlet and outw let pipessfie-andelvl respectively, these pipes also serving as a. handle for the tray. s-Extension portionSABzand-Ahare joined by cross-piece 42. The entire eextension .is .pivotally secured by crosspieceizesecured to .pin 43 carried by the "tray flanges. .JIhe extension has;handle 45 in proximity to pipes 36 and 31. The tray properhas bottom portion .apertured at- 48 for vaccommodatingitongueifl carried by extensionAO. .Tongue .fillhas-humpszfi l and-52 cooperating -with.the side .of :slot A8etoeprovide a lock. in generally the same mannerethat the .clips function in. Figures 5 and .6.

.Theconstruction-shown .in "Figure '7 -may be .opened so.that the perforated extension is-.clear of the tray proper to promote filling-of thetray with --impression-forming material. In the use nf=a'tray:sueh as shown in Figure '7, it-may'be found-desirable toprovide dams -at--the twoi tray endswnd along the: edges J for; preventing flow of impression formingmaterial at I the ends. .These dams may .be formed of temporary impressions-:of

.the-.teeth=. or ;.gums';against'.whichithese may: nor :mally rest. -Such:dams may be;.ma.de:0f. materialsnowrinzgusein dentalofiices and, when-Edisp0S6d::2.tT.the:.tWO16I1dS of the tray, will :provide sufiicient-sealingpaction so that proper .operation may :result.

.In the use-ofeazstructureembodying. thepresent invention, the :tray; proper -will belfilled with. impressioneforming "material in ithe conventional -manner. .BThBiBXtEHSiOII in Figure 1,.for-zexample,

till

4 will then be in its upper position. The tray is thereupon inserted into the oral cavity and disposed firmly in position against the surfaces to be impressed. Thereupon the dentist or technician will begin to push handle it: and the tray against handle 30 so that the extension and tra proper are slowly forced into a closed position while the entire tray is maintained tightly in position against the impression-forming surface. Due to the-back pressure created by side120, impressionjforniing material will be pressed against the desired surface. While some impression-forming material may ooze out through the perforations,

' most'impression-forming material will escape over the free sides and edges of the entire tray By proper filling of the tray manipulation of the two portions of the tray with respect toeach other, it is possible for an operator to obtain a desired impression without the use :ofsanizexcessiveiquantity ;of the impressione forming "material.

iltsis :possible ito shave ithe ttrayiflange ."on zthe insideuofzthe extension-when :closed and suchza constructionzis shown.in;.Figur-e 8. Thus .refer- :ring to :Fkigures8; tra proper 255 has :auxiliary member-15.6 pivoted;ati51. The viewzonly:shows;.a .detail-zof this, it beingiunderstood ;that..the 3T6- mainder:isssimilarlyrprovided. with vaipivotedsportion in a manners-generallygsimilar to Figures 1 :an'd-3 asifanaas-athose:trayseare concerned. It is understood, of :course, that "the :same construction 10f @the auxiliary member outside :the :tray properunay .be applied to: the :constructionzshown .inzFiguret'l. Irr Figure-18,:thezanxiliarysmemberiis shown as zh-aving: small spines orrroughenings-cBB on -the inside-surface of therauxiliaryimembenior anchoring the. compound: to theeauxiliary, member material.

:The constructionof theztray; shown-in Figure il may be modified, if desired, .byi 'havingthe'rrear portionithereofi extend; straightacross f rom': heel to heel :with; pivot means disposed .alongithisa con- .tinuouszportion.

xeAssubstantial advantage accruing from the use ..of1the :present. inventiomlwill .become manifest in :connection .rvithithe manufacture of plaster of .Parisrcasts from'the impression. As is well known, *anlimpression :..of compound I in 'a 5 tray "--is' first IOIHIGdiZJIdEthBIBEftGI asplaster of *Paris east of this impression must be made. After the plaster ofiRarisz-has set, lit isnecessary to separate the aplasteroflParis'cast from the compound and tray. Due to-rthe-reinforcing aetion of thetray walls Ithetcomponnd does not yield -verymuch when -an:; attemptiismade to. pull the" plaster of' Paris cast away. In such =anoperation; i ay occur .ithatf-proj eetingportionsof the cast," corresponding to ill forme'd teethin the patients'moutmwi'll 'bestrained arid' broken. By virtue of" the present invention;- it is--sim-ple=to'swing the-auxiliarynnem bep arid -castaway from-the-tray proper. Hence the cast may he readily-removed"from' thei auxiliary member.

'What isolaimedis *1. A'plental' tray'assemblyicomprising. a.tray proper shaped to h'olcl fimpression forming compound-for-*oral-- prosthetic work, said: tray proper ha vingwidge and fiange'portions, and an auxiliary-member having 'the. same general shape 'as the flange proper but-having: substantially 'no ridgeportion, said-auxiliarymember being dimen- 'sioned to telescope saidllangeandi'being adapted to be --foreed in-to telescoping relation'with' the tray" proper "during the -taking of an impression whereby the impression-forming compound is subject to pressure generated during the telescoping action and flows along the impression surface.

2. The structure according to claim 1 wherein said auxiliary member is pivotally secured to the tray proper. I

3. A dental tray assembly comprising atray proper shaped to hold impression-forming compound for oral prosthetic work, said tray proper having ridge and flange portions and an auxiliary member having the same general shape as the flange of the tray proper but not having any substantial ridge portion, said auxiliary member being dimensioned to telescope within the tray proper along the flange portion, said auxiliary member being forced into telescoping relation with the tray proper during the taking of an impression with the impression-forming compound flowing under pressure along the impression surface.

4. The structure according to claim 3 wherein said auxiliary member is pivotally secured at the rear or heel portion of the tray proper.

5. A dental tray assembly comprising a tray proper shaped to hold impression-forming compound for oral prosthetic work, said tray proper having ridge and flange portions, said tray proper having heel and labial portions with a handle extending from the labial portion of the tray proper, an auxiliary member having the same general shape as the flange portion of the tray proper but having substantially no ridge portion and being dimensioned to telescope said flange portion, means for pivotally securing said auxiliary member and tray proper at the heel portion of the tray proper so that the auxiliary member may move in or out of the labial portion of the tray proper and means carried by the labial portion of said auxiliary member and cooperating mined open position for initiating impression tak- -ing.

v 8. The structure according to claim 5 wherein said tray proper has a vault portion. 9. The structure according to claim 5 wherein said tray proper has a lingual flange portion and wherein said auxiliary member has a corresponduing lingual flange portion.

' g ,3. 10. The structure according to claim 5 wherein said tray proper is of the type for use with bridges and wherein the auxiliary member and tray proper have labial and lingual flanges.

11. The structure according to claim 5 wherein one movable part carries a spring clip and the other movable part has means cooperating with ,slpring clip for limiting the movement of the two I members with respect to each other.

' HARRY SPIRO.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 883,055 Smith Mar. 24, 1908 I {981,476 Rowse Jan. 10, 1911 2,426,388 Chartrand Aug. 26, 1947 

